An advanced-super dimensional switching (ADS for short) mode is a core technology for a plane electric field and wide viewing angle display. Specifically, an electric field generated at the edges of a slit electrode in the same plane and an electric field generated between the slit electrode and a plate electrode form a multi-dimensional electric field, so that all oriented liquid crystal molecules positioned among slits of the slit electrodes and right above the electrodes in a liquid crystal cell may deflect, and the image quality of liquid crystal display is improved.
In a high-resolution display device adopting the ADS mode, because the unit area of a sub-pixel is relatively small, the storage capacitance is insufficient. Therefore, in the prior art, common electrode lines need to be manufactured on a gate layer to increase the storage capacitance. However, the design of the effective area of the common electrode lines is limited due to the limitation of resolution of exposure equipment. Meanwhile, as shown in FIG. 1, FIG. 2 and FIG. 3, the common electrode lines 1 are positioned nearby the tail ends of slits 21 of first electrodes 2 (slit electrodes) and are light-tight, whereas parts of substrate nearby the common electrode lines 1 are light-transmissible, two sides at the edges of the common electrode lines 1 are in a light blocking state and a light-transmitting state respectively in the manufacturing process of the slit electrodes, and the two states would produce different influence on light in the photoetching process, so that the thickness of a photoresist therein is non-uniform after photoetching, then patterns therein are deformed in the subsequent etching processes, the patterns at the tail ends of the slits 21 of the slit electrodes deviate from the predesigned patterns, the liquid crystal molecules therein deflect undesirably, a trace mura phenomenon is produced, and the quality of displayed images is affected.